I have tried to learn this on the net but most pages assume the reader has a lot of background experience in theoretical physics.  So could anyone shed some light on this for me?
Thanks,  
Justin Ward

I'm not even going to attempt it, but this thread could very easily turn into a [b]long[/b] one.

Sit on a hot plate for one minute and it seems like one hour.
Talk to a beautiful woman for one hour and it seem like one minute.

That’s relativity.

My a$$ at rest, stays at rest unless acted upon by some outside "nagging" force.

E (energy) = M (mass)  times C squared (C is the speed of light).  So every quantity of mass you can change to energy is the amount of mass times the speed of light squared (a very very large number even with only a few atoms of mass).  So we split the atom,  a small part of the mass turns to energy during the split and we get a huge explosion (which is a lot of energy).  

But don't try it at home.  
[grenade]

At it's simplest, there is no absolute frame of reference.  All measurements of position and motion are relative to something else which is in turn relative to something else ...

If you do not live in Bay Tree, you would be best off reading a delightful little book by a nice fellow called Thomas M. Helliwell.  I imagine you could email him and ask him where you could get buy a copy.  

My flawed understanding of relativity is that it is a construct that better predicts the behavior of objects that move at speeds that are a few orders of magnitude within the speed of light.  Under these conditions, Newtonian mechanics fail, although NM is perfectly useful for bullets, cars and non-c rhinos.

The well known e=mc^2 is part of the theory, but it also encompasses time shifts and other stuff that I didn't learn adquately.  So I failed out :)

Relativity has two postulates:
1. [b]The postulate of Relativity[/b].
The laws of physics are the same for observers in all inertial reference frames. No frame is singled out as preferred.

2. [b]The postulate of the speed of light[/b].
The speed of light in free space has the same value c in all directions and in all inertial reference frames.

First postulate is that [i]ALL[/i] laws of physics (Newtonian, electromagnetism and optics) stay the same, no matter whom you are, where you are or what you are doing.

Second postulate is basically that the speed of light is a constant.

Now comes the fun part of the second postulate, throws everyone for a bit of a loop with this concept experiment:



Here is the kicker on why; the second postulate is only talking about LIGHT. It doesn’t make any reference to mechanical waves (sound) or particles (like a baseball). Light is on its own, freaky thing of a waving-particle concept.

Einstein theory of relativity is really simple on it’s own, it is once that you start playing around with it gets difficult.

(edited for formating)

Where's McUzi and his giant mensa brain when you need him?

Tell you what... I'm currently reading a book called E=MC2, it's a simplification/explanation, in laymans terms, of what the theory is and what it's ramifications are.  If you want I'll loan it to you, but you gotta send it back when you're done.  

I've read the first few chapters which break down each part of the equation (no math, just the history of energy theory, mass theory and why the speed of light is so important).  The author is concise and easy to follow and has made what I've read so far understandable.  You might like it... I should be done in a week or so.

I can't really tell you what the Matrix is. It'll just be easier if I show you.

Blue pill or Red pill?


Sherm

You mean I'll be able to dodge bullets?
Once you believe, you won't need to.

The General Theory or the Special Theory?

Hey what happens if you travel faster than the speed of light.Also does light bend or change color the faster we travel?

Boy, I'm glad I read all the posts above as I was about to say uh uh uh exactly all that "Guzzler" said that is accurate.
[:D]

Let's say you are traveling in a car at the speed of light and there is another car right behind you also traveling at the speed of light.

If the car behind you turns on its headlights will you be able to see them?

Maybe, but it might depend.
[:D]

No.




But this will help:
[url]www.multimania.com/bvr/rele01.html[/url]

[url]www.perkel.com/nerd/relativity.htm[/url]

I'm a physics major, well was before I dropped out of school(returning this fall).  The theoretical stuff is out there man, but you just have to loosen your head a little and you can get it.  To simplify what has been stated the biggest point in relativity IMO is that every person perceives things differently.  Example.  The old riddle of throwing a ball 30 mph on a train traveling at 60mph.  Well if the train was passing a stationary observer the ball would "appear" to be traveling 90mph given the obeserver was directly perpendicular to the line of flight of the ball at said velocity.  Simple right?  Well it isn't.  Imagine this. If you were in a rocket ship and traveling at the speed of light and you turned on a flashlight as you passed another statioary observer would ther beam of light "appear" to be moving at twice the speed of light(velocity of the rocket+beam of light from the flashlight)?  No.  The speed of light is absolute(as far as we have been able to prove thus far) in all frames of reference.  It will measure 286K mps no matter the position or velocity of the source or the observer.  So Relativity is just that, everything that happens is relative to the observer except for the velocity of light.  So what is so big about this?  Well it is explained in laymens terms very well in a book titled "A Brief History of Time" by Stephen Hawking.  It was required reading in a class I had and it helped explain some of the hard to comprehend stuff.  A great read!

The big push is now to unite everything into a "Grand Unified Theory"  The laws that govern the large scale workings of the universe break down on the sub atomic level so science it trying to resolve a theory that unites quantum mechanics with astrophysics.  There is one system that creates or relies on the existance of 7 other dimensions besides the 4 obvious ones we live in to work.  Now beyond that it gets really wild.  I hope this helps.

Jarhead it is not possible(yet) to travel faster than light.  The Doppler effect is what you are referring to and there is a similar phenomena with light.  It is called the red shift.  It was observed that there is a steady and unwavering background noise of microwave radiation in space that is constant in every direction that we look in space.  This is actually the remnants of visible light and energy emminating from the big bang and as the universe expands, light travels at the same constant, the frequency lowers.  Imaging it as the waves of light stretching out but not slowing down(best visualization I can give).  I'm getting beyond myself now.

For a more scientific treatment of this subject I recommend the reading of "Dune."

Pretty good succinct explanation Valkyrie.






.





[i]BTW, that's [u]ONE[/u] hundred and eighty six thousand miles per second
(Yeah, I know you knew that - sorry).[/i][;)]

186,000 miles per second... not just a good idea, it's the Law![;)]

one more attempt to explain the theory of relativity.
first off, there are 2 theories of relativity.
there is the special theory, and the general theory.
the special theory deals with the relationship between motion and time. it also is a theory where the assumption is that the speed of light is the upper limit of velocity, and the speed of light is the same for all observers. basically if I get on a craft traveling the speed of light, and you stay here on ar15.com, time slows down for me in relation to the time you observe. this has been proven by scientists using high speed aircraft and atomic clocks.
the general theory deals with mass and motion. and basically the larger the object, the higher the gravitational field of the object, and the faster (velocity) the object travels the greater the mass of the object, also large objects with more gravitational fields actually warp and deform space.
as a caveat id like to say im not a physicist I only play one on ar15.com.

one more attempt to explain the theory of relativity.
when the sweat of your balls runs down the crack of your cousins ass....oh wait, thats relative humidity, not theory of relativity...never mind

You can get a good look at a steak by sticking your head up your butchers ass.....wait a minute...it's gotta be your bull....[%|]

EX11B, I think that'd qualify as general relativity too.[:D][:D][:D]
Just good `ol, simple, non-theoretical AZ relativity.[:D][:D][:D]

Yeah, 186K I type lousy sorry!

Physics just absorbs my attention.  Had a 4 hour discusion with one of my professors once dealing with the effect of gravity on light and the duel property of light(partical/wave).  Some amazing possibilities.  

Did you know there is a such thing as a graviton?  It is a theoretical partical or wave that is the basis of gravity and it is theorized that it travels also at the speed of light.  Until college I thought it was some hollywood technobabble from a science fiction writer.  Consider that time/space can be bent by gravity.  And enough gravity, in theory could bend it 180 degrees back onto itself.  Now if that is so then with a theoretical device we could "warp" space around to travel forward or backward in time by traveling a RELATIVLY short physical distance.  Maybe?  It has been theorized that this occurs at the event horizon of a black hole.  The threshold where escape by anything is not possible but at the very edge space is warped back around to itself.  It is theorized that all physical laws break down beyond this threshold and no predictions of time, space, or matter can be formulated beyond this point.  Unreal!  

Believe Einstein also said, "If you really know your subject, you can explain it to a 7 year old."

Thanks Valkyrie, Guzzler, et al.

"As you go faster, approaching the speed of light, your time will seem slower compared to someone on earth standing still."

CanadianGunNut,

    Weren't you the one asking about Radio Shack stereo equipment the other day?  You sure move fast!  What are you building, a bomb or something?  Ask the other board members about the foolproof A$$ bomb, much better than the shoe bomb...

To travel at the speed of light would take an infinite amount of fuel; let alone the speed of light squared.
Which is impossible. :)

Sorry man, but that would be "Wifey's first law of Commotion."

E=mc2

Where:

E=embezzlement
m=malevolent failed dot com goatee heads
c=contrived profit reports

Try this on:

Einstein's theory of special relativity holds that all things are subject to the effects of time. But the perception of the passage of time is relative to the [i]frame of reference[/i] for different objects traveling at different speeds. To understand this, let's set up a scenario.

Say that you are in a ship and I'm standing on the ground, and (somehow) we are both able to view each other. You begin accelerating towards the speed of light, while I remain here on Earth. As you get very close to the speed of light, you perceive that I appear to be aging ever more rapidly, but I perceive that time is slowing down for you (i.e. You aren't aging at the same rate that I am). However, we perceive the passage of time within our individual [i]frames of reference[/i] as normal.

Now, suppose you reach the speed of light. Relative to your [i]frame of reference[/i], my entire life would have occurred in a single instant. In fact, everything existing in my time frame will have occurred in a single instant - relative to your timeframe, that is.

I, on the other hand, would perceive you as ageless. If you continued accelerating beyond the light speed threshold, you would perceive that time is in reverse for me (In effect, you'd be traveling backwards with reference to my time frame). Things get trickier when you cross this threshold, and certain theories "blow up". Remember, all the while, from within our own [i]frames of reference[/i] (You in the ship & me here on Earth) time continues to pass along normally.

Still confused? Let me push you further towards insanity[whacko] Say that, rather than continuing to accelerate towards the speed of light, you returned to where I'm at. From your [i]frame of reference[/i], by your own watch, you will perceive that it took much less time for the whole trip, while my watch will tell me that you took much longer. A [i]time dilation[/i] has occurred - relative to the passage of time back here on earth, time has been compressed/reduced for you, but stretched/expanded for me.

The quantitative [i]time dilation[/i] that has occurred is described by Lorentz transforms, the details of which are too lengthy & unnecessary to get into here. Suffice it to say that, time displacement is [b]not[/b] linear (Meaning that, a Lorentz transform calculation does [b]not[/b] simply subtract away some X quantity of time from your time frame and then just add that X amount to mine. It's more complex). For this discussion, those details are unimportant. What is noteworthy is that we both perceived the passage of time differently because we perceived it from different frames of reference, because we were at different [i]speeds[/i].

Caveat emptor: some of this is theoretical, and some (as mentioned), has been actually been proven.

[b]cont'd[/b]...

...[b]cont'd[/b]

Here's a slightly simpler analogy:

You've probably heard the phrase, "Time is like a river", so consider time this way. Suppose we're both in our own boats, side-to-side on the "river of time". The perception of time is the same for us both. Now, if you row ahead of me (that is, speed up, relative to my position in time), then you've covered water that I have yet to cross - a time interval I haven't yet spanned. You've encountered more water (more of the events in my life) than I. So, the water in my path - my timeline of events - appears to have passed by more quickly relative to your vantage. Meanwhile, I still have yet to encounter the water (events in time) in my path that you've already crossed.

Remember that in this scenario, the river represents a single timeline that I'm in, but which you can traverse. Your perception of the timeline for me is important. You perceive the water - the passage of events in time for me - more quickly than I do.

Now suppose, again, that we're both wearing watches. Since you've covered more water (The passage of events in my life) than I have, and our watches both tick along at exactly the same rate, then according to your watch, the water in my path - the events in my life - has passed by more rapidly. On the other hand, since your watch didn't speed up as you moved ahead on the river (you moved forward in time), I conclude that for you, time must have passed more slowly.

Relative to our perceptions of each other, these conclusions are true – the events of your life do "slow down" relative to my timeline, while mine "speed up" relative to yours. But within our own frames of reference (our perception of time's passage in our own lives), time remains constant.[whacko]

[b]What have we learned?[/b]:

1. Within their own [i]frame of reference[/i] time passes at the same rate for all objects. The difference is in the relationship between different time frames.

2. The perception of time is relative to an object's own time frame reference. Relative to its time frame, a faster moving object perceives that the passage of time is faster for slower objects. Conversely, a slower object perceives that time passes more slowly for the faster object.

3. Some of the board members on AR15.com are crazy - especially that "Master Blaster" dude.

4. If you're 21, you need a tall drink. If you're not, accelerate beyond the speed of light and then put yourself back somewhere in this timeline so that you'll be 21 by the time I have posted this, and then pour yourself a drink. [beer]

5. F*#%ing Einstein. No wonder his hair looked the way it did.

Bartender, make mine a double (barrel)[heavy][beer][:D]

Theory of Relativity?
Isn't that when the boss' moron son-in-law gets the promotion that you deserve?

[b]" If she's related to u, she's OFF LIMITS!"[/b]

Mike

IIRC Douglas Adams wrote about this in his Trilogy (of four books). Relativity depends on where you want to eat, when you want to eat and who is picking up the bill. [:)]


Edited to add that what you want to eat opens up the carnivorous vs. vegetarian discussions.

[b]To travel at the speed of light would take an infinite amount of fuel; let alone the speed of light squared.
Which is impossible. :)[/b]

This never really made sense to me because something funky happens with mass increasing .. so I think there should be a porportional increase in thrust....

Because rockets are propeled by venting mass in the opposite dircetion (newton equal and opposite reations) so a increase in the mass of the propelent should result in the increase in speed...



    Relativity is simple, you want someing complicated look up the superstring theory [):)]

 The reason that traveling at the speed of lightmis impossible under the theory of relativity is that using E=MC2, once a physical object attains light speed, it also attains infinite mass, which is impossible.[(:|)]

No matter how fast the rocket goes, the velocity of the propellant relative to the rocket doesn't change.  Therefore, the mass of the propellant relative to the mass of the rocket doesn't change either and there's no increase in thrust.

The theory of relativity -

Unlike Dianne Feinstein who carries a concealed weapon, you are NOT to be allowed to carry a concealed weapon. Unless you are her relative....

Bistro math?  I haven't thought of that in forever! HAHAHA

Yeah. That too. But let me revise this just a bit: Relative to D.F., you're a peon serf, so you can't have any(thing). Back to your hovel.

This is where the energy goes instead of increasing visable speed in the three visable dimensions:

From [url]http://www.perkel.com/nerd/relativity.htm[/url]
best explination I have yet seen in writing.